1. Field of the Invention
The present invention relates to a control apparatus for a vehicular alternator, and more particularly, to a new technique for achieving improved reliability and cost reduction.
2. Description of the Related Art
A known control apparatus for a vehicular alternator operates to switch the alternator so as to be connected to a circuit that consumes energy due to a field current, by the use of a resistor, a diode, etc., in order to quickly reduce the field current (see, for example, a first patent document (Japanese patent application laid-open No. 2003-174799)).
In such a known control apparatus for a vehicular alternator, a first attenuating circuit and a second non-attenuating circuit are switched over from one to the other by the use of two switches, thus resulting in a problem that the structure of the control apparatus becomes complicated and expensive.
In addition, since the first and second circuits have diodes, respectively, there is another problem that the number of component parts is increased, thereby making the control apparatus further expensive.
Moreover, if the two switches are turned off at the same time, there will be a possibility that the control apparatus might be destroyed by an overvoltage, so there is a further problem that an additional circuit is required so as to avoid this, thus making the structure of the control apparatus further complicated.